A group of Poway residents bring flowers and cards to a memorial outside of the Chabad of Poway synagogue, Sunday, April 28, 2019, in Poway, Calif. A man opened fire Saturday inside the synagogue near San Diego as worshippers celebrated the last day of a major Jewish holiday. (AP Photo/Denis Poroy) (AP Photo/Denis Poroy)

The FBI said Monday that it received tips on a threatening social media post about five minutes before a gunman burst into a Southern California synagogue and opened fire with an assault-style rifle, killing a woman and wounding a rabbi and two others.

The tips to the FBI’s website and phone number included a link to the anonymous post but did not offer specific information about its author or location of the threat. The FBI said employees immediately tried to determine who wrote the post, but the shooting occurred before they could establish his identity.

“The FBI thanks the alert citizens who saw and reported the post,” the agency said.

One of the tipsters told The Associated Press that he called the FBI tip line at 11:15 a.m. Saturday because the post linked to a manifesto that said the author was responsible for a mosque arson in the city of Escondido last month. He says he found online that the mosque attack had happened and feared the new threat was real.

The tipster, who refused to provide his name because of security concerns, said the call with the FBI lasted four or five minutes and the shooting happened soon after. He described the FBI as quick and professional and said he doesn’t know what they could have done.

The shooting happened around 11:30 a.m. Moments afterward, police arrested 19-year-old John T. Earnest of San Diego. He is being held on suspicion of murder and attempted murder.

The online manifesto written by a person identifying himself as John Earnest was an anti-Jewish screed posted about an hour before the attack. The poster described himself as a nursing school student and praised the suspects accused of carrying out attacks on mosques in New Zealand that killed 50 people last month and at Pittsburgh’s Tree of Life synagogue that killed 11 on Oct. 27.

About 100 congregants were worshipping at the Chabad of Poway near San Diego on the last day of the Jewish holiday of Passover, which celebrates freedom, when the gunman killed Lori Kaye, 60. He also wounded the synagogue’s rabbi, Yishoel Goldstein; Noya Dahan, 8; and her uncle Almog Peretz.

Goldstein said he was preparing for a service and heard a loud sound, turned around and a saw a young man wearing sunglasses standing in front of him with a rifle.

“I couldn’t see his eyes. I couldn’t see his soul,” Goldstein said. He raised his hands and lost one of his fingers in the shooting.

And then, Goldstein said, “miraculously the gun jammed.”

In the moments that followed, Goldstein said he wrapped his bloodied hand in a prayer shawl and addressed congregants gathered outside the building, vowing to stay strong in the face of the deadly attack targeting his community.

“We are a Jewish nation that will stand tall. We will not let anyone take us down. Terrorism like this will not take us down,” Goldstein recalled telling the community.

Authorities said Earnest had no previous contact with law enforcement and may face a hate crime charge in addition to homicide charges when he’s arraigned later this week. He was being held without bail, and it was unclear if he had an attorney.

Police searched Earnest’s house and said he was also being investigated in connection with an arson attack on a mosque in nearby Escondido, California, on March 24.

There were indications an AR-type assault weapon might have malfunctioned after the gunman fired numerous rounds inside, San Diego County Sheriff William Gore said. An off-duty Border Patrol agent fired at the shooter as he fled, missing him but striking the getaway vehicle, the sheriff said.

Shortly after fleeing, Earnest called 911 to report the shooting, San Diego Police Chief David Nisleit said. When an officer reached him on a roadway, “the suspect pulled over, jumped out of his car with his hands up and was immediately taken into custody,” he said.

Goldstein described Kaye as a pioneering founding member of the congregation and said he was heartbroken by her death. He said the attack could have harmed many more people had the shooter turned toward the sanctuary where so many were praying.

“Lori took the bullet for all of us,” the rabbi said, his hands wrapped in bandages. “She didn’t deserve to die.”

He said that Kaye’s physician husband was called to tend to a wounded worshipper and fainted when he realized it was his wife.

Friends described Kaye as giving, warm and attentive to community members on their birthdays and when they were sick. A wife and mother, she loved gardening and made delicious challah for her family and friends, said Roneet Lev, 55.

When the gunfire erupted, another worshipper, Shimon Abitbul, said he immediately placed his 2-year-old grandson on the floor and waited for a break in the shooting to grab the boy and sprint away.

Abitbul, who was visiting from Israel and staying with his daughter and her family in Southern California, said he was still coming to grips with the carnage.

“All of us are human beings,” he said. “It doesn’t matter if you are Jews or Christians or Muslims.”

Peretz, who was wounded in the leg, said he turned around after hearing gunfire and saw the shooter standing by the door. He grabbed his niece by the hand and carried out another child.

He then saw a group of children and got them running, “I tell them, ‘go this way, go this way,” said Peretz, who is visiting from Israel.

Gore said authorities were reviewing Earnest’s social media posts, including what he described as a “manifesto.” There was no known threat after Earnest was arrested, but authorities boosted patrols at places of worship Saturday and again on Sunday as a precaution, police said.

“It was a hate crime, no doubt about it,” national security adviser John Bolton said on “Fox News Sunday.” He said investigators have not seen any connection between the suspect and other extremist groups.

California State University, San Marcos, confirmed that Earnest was a student who was on the dean’s list and said the school was “dismayed and disheartened” that he was suspected in “this despicable act.”

Goldstein said President Donald Trump called him to share condolences on behalf of the American people.

The White House acknowledged the call. “The President expressed his love for the Jewish people and the entire community of Poway,” Deputy Press Secretary Judd Deere said in a statement.

On Sunday night, hundreds of people gathered at a park for a vigil to honour the victims.

People at the community park near Chabad synagogue in Poway held candles and listened to prayer in Hebrew. Leaders asked community members to do acts of kindness to remember Kaye.

Poway Mayor Steve Vaus said he would stand with the community, and Rabbi Goldstein said seeing the crowd come together provided consolation.

“What happened to us, happened to all of us,” Goldstein said.

Weber reported from Los Angeles and Balsamo reported from Washington. R.J. Rico in Atlanta, Elliot Spagat in Poway and Daisy Nguyen in San Francisco contributed to this report.

People gathering on a street corner hold signs in support of the victims of Saturday’s shooting at Chabad of Poway synagogue, Sunday, April 28, 2019, in Poway, Calif. A man opened fire Saturday inside the synagogue near San Diego as worshippers celebrated the last day of a major Jewish holiday. (AP Photo/Denis Poroy)

A couple holds candles during a vigil held for victims of the Chabad of Poway synagogue shooting, Sunday, April 28, 2019, in Poway, Calif. A man opened fire Saturday inside the synagogue near San Diego as worshippers celebrated the last day of a major Jewish holiday. (AP Photo/Denis Poroy)